Improvement in LC–MS calibration by addition of fragment signals

Variables selection methods in near-infrared spectroscopy

“…At the end of the net training, similar wavelengths fall within the same neuron, i.e., carry the same information. To select the set of wavelengths, it is assumed that the wavelength closest to each neuron centroid is the most representative of all the wavelengths within the same neuron [76].…”

Determination of non-steroidal anti-inflammatory drugs in pharmaceuticals and human serum by dual-mode gradient HPLC and fluorescence detection

“…Several methods have been reported for the assay of NSAIDs in pharmaceuticals and biological fluids; in general these works deal with a single compound or a few compounds, and employ capillary electrophoresis [10][11][12][13][14][15], spectrofluorimetry [16][17][18][19][20], flow injection fluorimetry [21] or gas chromatography coupled to mass spectrometry (GC/MS) [22][23][24]. GC methods are timeconsuming and have been largely replaced by HPLC methods with ultra-violet (UV) [25][26][27][28][29][30][31][32][33][34][35] detection, electrochemical detection [36], or mass spectrometry [37].…”

Multivariate analysis of nystatin and metronidazole in a semi-solid matrix by means of diffuse reflectance NIR spectroscopy and PLS regression

“…* The use of near infrared (NIR) spectroscopy methods to assess quantitative information of drugs in medicines has increased in recent years [1][2][3][4][5]. Other spectroscopic techniques, such as UV and fluorescence, together with multivariate treatment, have also been applied in quantitative studies, requiring solutions preparation to proceed with measurements [6][7][8][9]. NIR spectra, when treated using chemometric methods of analysis, such as partial least squares (PLS) regression, may provide identification and quantification of compounds in a second or higher order mixture, with little or no sample preparation.…”